Pressure vacuum release hermetic valve for flexible packages

Abstract

A flexible, gussetted package having an interior for holding some particulate material product, under vacuum, and which includes a mouth to be opened to provide access to the contents of the package. The package is formed of a flexible material and includes a front panel, a rear panel, and a pair of opposed side gussets and a pressure equalizing valve. The valve is arranged to operate in a first mode of operation wherein any gasses within the package are allowed to vent to the exterior of the package, while the ambient atmosphere is precluded from entering into the interior of the package. The valve also operates in a second, transitory, mode wherein it allows a small amount of the ambient atmosphere to gain ingress into the interior so that the package's walls give a smooth appearance. The valve then enters into its third mode of operation wherein it isolates the interior of the package from the exterior.

I claim: 
     
       1. A package having an interior for holding a particulate material therein, said package being formed of a flexible material and comprising a front panel, a rear panel, and a pressure equalizing valve, said package having an interior, said front and rear panels being connected to each other, said valve being coupled to one of said panels and in communication with the interior of the package and in communication with the exterior of the package, said package being formed of a material suitable for being hermetically sealed with the particulate material being located within the interior of said package, said valve comprising a flexible displaceable member having a peripheral edge and a slitted aperture, said slitted aperture having marginal edges normally in engagement with each other to prevent the passage of a gas therethrough, said valve having a first mode of operation wherein said displaceable member is deflected so that its marginal peripheral edge allows any gasses within said package to pass thereby to gain egress to the exterior of said package, while said valve precludes the ambient atmosphere at the exterior of said package from gaining egress into said interior, said valve also having a second mode of operation wherein said marginal edges of said slitted aperture of said displaceable member separate from engagement from each other to allow a small amount of the ambient atmosphere at the exterior of said package to gain egress into said interior through said slitted aperture, said valve also having a third mode of operation wherein said displaceable member is undeflected to isolate said interior of said package from said exterior. 
     
     
       2. The package of claim 1 wherein said valve automatically operates in said third mode when the pressure within said interior of said package is the same as the pressure at the exterior of said package. 
     
     
       3. The package of claim 2 wherein said front and rear panels exhibit a smooth appearance when said valve is in said third mode of operation. 
     
     
       4. The package of claim 1 wherein said valve automatically operates in said first mode of operation when the pressure within said interior exceeds the pressure at the exterior of said package. 
     
     
       5. The package of claim 1 wherein said valve operates in said second mode for a transient period of time until said valve operates in said third mode of operation. 
     
     
       6. The package of claim 2 wherein said valve automatically operates in said first mode of operation when the pressure within said interior exceeds the pressure at the exterior of said package. 
     
     
       7. The package of claim 2 wherein said valve operates in said second mode for a transient period of time until said valve operates in said third mode of operation. 
     
     
       8. The package of claim 6 wherein said valve operates in said second mode for a transient period of time until said valve operates in said third mode of operation. 
     
     
       9. The package of claim 1 wherein said valve additionally comprises a valve seat on which said peripheral edge of said flexible displaceable member is disposed, said slitted aperture in said flexible displaceable member being in the form of at least one slit. 
     
     
       10. The package of claim 9 wherein when said valve is in said first mode of operation, said flexible displaceable member is lifted off of said valve seat to allow any gasses within said package to gain egress to the exterior of said package, while precluding the ambient atmosphere at the exterior of said package from gaining egress into said interior. 
     
     
       11. The package of claim 9 wherein when said valve is in said second mode of operation, said flexible displaceable member is disposed on said valve seat in a sealing abutment, but with said at least one slit being partially open to allow a small amount of the ambient atmosphere at the exterior of said package to gain egress into said interior. 
     
     
       12. The package of claim 9 wherein when said valve is in said third mode of operation said flexible displaceable member is disposed on said valve seat in a sealing abutment and with said at least one slit being closed to isolate said interior of said package from said exterior. 
     
     
       13. The package of claim 10 wherein when said valve is in said second mode of operation, said flexible displaceable member is disposed on said valve seat in a sealing abutment, but with said at least one slit being partially open to allow a small amount of the ambient atmosphere at the exterior of said package to gain egress into said interior. 
     
     
       14. The package of claim 13 wherein when said valve is in said third mode of operation said flexible displaceable member is disposed on said valve seat in a sealing abutment and with said at least one slit being closed to isolate said interior of said package from said exterior. 
     
     
       15. The package of claim 9 additionally comprising a viscous material interposed between said valve seat and said flexible displaceable member. 
     
     
       16. The package of claim 15 wherein said viscous material comprises silicone oil. 
     
     
       17. The package of claim 1 additionally comprising filter to preclude the particulate material within said package from gaining ingress into said valve. 
     
     
       18. The package of claim 1 wherein said package is gussetted. 
     
     
       19. The package of claim 1 wherein said package includes an openable mouth. 
     
     
       20. A pressuring equalizing valve for use with a flexible package holding particulate material, the package being formed of a flexible material and comprising a front panel and a rear panel, and defining therebetween an interior in which the particulate material is disposed, said valve being arranged to be coupled to one of the panels in communication with the interior of the package and in communication with the exterior of the package, the package being formed of a material suitable for being hermetically sealed with the particulate material therein, said valve comprising a flexible displaceable member having a peripheral edge and a slitted aperture said slitted aperture having marginal edges normally in engagement with each other to prevent the passage of a gas therethrough, said valve having a first mode of operation wherein said displaceable member is deflected so that its marginal peripheral edge allows any gasses within the package to pass thereby to gain egress to the exterior of the package, while said valve precludes the ambient atmosphere at the exterior of the package from gaining egress into the interior, said valve also having a second mode of operation wherein said marginal edges of said slitted aperture of said displaceable member separate from each other to allow a small amount of the ambient atmosphere at the exterior of the package to gain egress into the interior through said slitted aperture, said valve also having a third mode of operation wherein said displaceable member is undeflected to isolate the interior of the package from the exterior. 
     
     
       21. The valve of claim 20 wherein said valve automatically operates in said third mode when the pressure within the interior of the package is the same as the pressure at the exterior of the package. 
     
     
       22. The valve of claim 20 wherein said valve automatically operates in said first mode of operation when the pressure within the interior exceeds the pressure at the exterior of the package. 
     
     
       23. The valve of claim 20 wherein said valve operates in said second mode for a transient period of time until said valve operates in said third mode of operation. 
     
     
       24. The valve of claim 21 wherein said valve automatically operates in said first mode of operation when the pressure within the interior exceeds the pressure at the exterior of the package. 
     
     
       25. The valve of claim 21 wherein said valve operates in said second mode for a transient period of time until said valve operates in said third mode of operation. 
     
     
       26. The valve of claim 25 wherein said valve operates in said second mode for a transient period of time until said valve operates in said third mode of operation. 
     
     
       27. The valve of claim 20 wherein said valve additionally comprises a valve seat on which said peripheral edge of flexible displaceable member is disposed, said slitted aperture in said flexible displaceable member being in the form of at least one slit. 
     
     
       28. The valve of claim 27 wherein when said valve is in said first mode of operation, said flexible displaceable member is lifted off of said valve seat to allows any gasses within the package to gain egress to the exterior of the package, while precluding the ambient atmosphere at the exterior of the package from gaining egress into the interior. 
     
     
       29. The package of claim 27 wherein when said valve is in said second mode of operation, said flexible displaceable member is disposed on said valve seat in a sealing abutment, but with said at least one slit being partially open to allow a small amount of the ambient atmosphere at the exterior of the package to gain egress into the interior. 
     
     
       30. The valve of claim 27 wherein when said valve is in said third mode of operation said flexible displaceable member is disposed on said valve seat in a sealing abutment and with said at least one slit being closed to isolate said interior of the package from the exterior. 
     
     
       31. The package of claim 28 wherein when said valve is in said second mode of operation, said flexible displaceable member is disposed on said valve seat in a sealing abutment, but with said at least one slit being partially open to allow a small amount of the ambient atmosphere at the exterior of the package to gain egress into the interior. 
     
     
       32. The valve of claim 31 wherein when said valve is in said third mode of operation said flexible displaceable member is disposed on said valve seat in a sealing abutment and with said at least one slit being closed to isolate said interior of the package from the exterior. 
     
     
       33. The valve of claim 27 additionally comprising a viscous material interposed between said valve seat and said flexible displaceable member. 
     
     
       34. The valve of claim 31 wherein said viscous material comprises silicone oil. 
     
     
       35. The valve of claim 20 additionally comprising filter means to preclude the particulate material within the package from gaining ingress into said valve means. 
     
     
       36. The valve of claim 20 additionally comprising filter means to preclude the particulate material within said package from gaining ingress into said valve means and a viscous material interposed between said valve seat and said flexible displaceable member.